For certain arterial diseases (e.g., peripheral arteries including the iliac, femoral, popliteal and tibial arteries) where plaques have built up onto the internal surface of blood vessel walls or thrombus in some cases (i.e., arterial occlusive disease), it is known to use a variety of techniques to improve blood flow through these vessels including, for example, angioplasty, stents or atherectomy. Angioplasty or stenting is believed to be ineffective when plaques may include irregular, loose or calcified deposits as these techniques simply compress the plaques further into the blood vessel walls with the attendant risk of vascular injuries. Atherectomy, on the other hand, where the plaque is physically removed, is believed to be more effective for calcified, fibrotic, as well as soft or longer lesions or lesions involving side branches in the peripheral arteries. The benefit of atherectomy is believed to arise from a reduction of plaque burden on the arterial wall that apparently does not affect the rest of the vessel walls post treatment.
Currently, several atherectomy devices are available on the market with FDA approval. These devices are categorized as laser ablation, orbital, rotational or directional atherectomy devices. Examples of such devices are described in U.S. Pat. Nos. 6,565,588; 7,674,272; 8,377,037; and “Atherectomy in the Treatment of Lower-Extremity Peripheral Artery Disease: A Critical Review” by Girish R. Mood, Md., Juyong Lee, Md., PhD, Lawrence A. Garcia, Md.; St. Elizabeth's Medical Center, Tufts University School of Medicine, Division of Interventional Cardiology and Vascular Medicine, Boston, Mass. (2013).
It is believed that some of these devices may facilitate the risk of plaque dissection due to the non-symmetrical cutting mechanism geometries and operational parameters. Some of these devices may not be as precisely controlled during the procedure due to the high rotational speed of the cutting tip or the non-symmetrical orientation of the cutting tip to the arterial vessel, which may lead to a phenomenon known as “whipping” of the atherectomy catheter. Whipping of the catheter may cause serious injuries including puncture of the artery.